The previous arms treaty between the two countries, known as START, expired in December last year.

Russia's Deputy Foreign Minister, with whom William Burns has talks today, says the understanding between Moscow and Washington is better than it's ever been.

“I support the classic approach to any negotiations,” said Sergey Ryabkov. “Nothing is agreed upon until everything is agreed upon.”

“Almost everything that separated the sides at the time when the talks began has now been worked through. Our leaders say that these are more technical things that will be discussed, they can be solved in a very short period of time,” Russia's Deputy Foreign Minister, told RT.

“The agreement that we are working on at the moment is the first agreement of that sort in the history of the Russian Federation. The old agreement was rooted in the Cold War, but now we have reached a completely different level of trust and a mutual understanding. Moscow and Washington are not suspicious of each other. All this is now being transferred into an agreement,” he said.

“There is organic, not virtual, interrelationship between strategic offensive arms and strategic defensive arms and it was first brought to light by the American side while preparing the ABM treaty of 1972,” political analyst Vladimir Kozin recalled.

“At the Moscow summit last July both presidents [Dmitry Medvedev and Barack Obama] once again reiterated their commitment and stressed the need to incorporate this linkage into the newly updated START treaty,” Kozin said.